John B. wrote in
:

On Sat, 2 Nov 2013 14:09:33 +0000 (UTC), Andrew Chaplin
wrote:

Anyone have any experience with these? I bought one last summer and it
would work fine for several hours in its flashing mode. Now that
weather has dropped below freezing, however, it runs for only about 15
minutes before shutting off; in other words, I cannot get home with the
damn thing still working. I had been as careful as I could to fully
discharge it and then charge it fully, but that does not seem to have
helped.

Temperature effects battery output, see:
http://www.discover-energy.com/why-d...uch-dramatic-e
ffect-batteries-0

This might be your problem if your bike/batteries are kept at outside
temperatures. In cold weather.

I'm a Canadian and a soldier who is trained in winter warfare. I know well
the effect of temperature on batteries, especially rechargeable ones. I
just hadn't expected it to be so severe. I suspect that the Flea, with its
tiny battery, is particularly vulnerable.
http://www.blackburndesign.com/lights/safety-lights-
front/rechargable/flea-2-0-front-usb-457.html

Try taking the light (and battery) off the bike and keeping it in a
warm location to see whether that lengthens the life a bit. that
should help identify the problem.

The light and battery are a single sealed unit that is always indoors when
it is not in use. I have cleaned the contacts on the charger and the light
and recharged it again after letting it go flat. I'll see if that helps.
--
Andrew Chaplin
SIT MIHI GLADIUS SICUT SANCTO MARTINO
(If you're going to e-mail me, you'll have to get "yourfinger." out.)